G06.27 Release Version Update Compendium

G06.27 Release Version Update Compendium—540430-001
2-1
2 Operating System
The G06.27 RVU contains these changes for the HP NonStop operating system:
•
Nonblocking Terminal I/O with OSS $ZTTnn
•
OSS Fileset
•
OSS Security APIs
Nonblocking Terminal I/O with OSS $ZTTnn
The HP NonStop Open System Services (OSS) environment has implemented a new
terminal helper server process, $ZTTnn (where nn is the processor number), in each
processor. The terminal helper server provides support for application use of the
select() function and the FILE_COMPLETE_ family of procedure calls on terminal
device files such as Telserv and OSSTTY. Each terminal helper server process is
automatically started when the processor it runs on is started. You cannot stop or start
the new process independent of processor shutdown or bringup.
OSS Fileset
The HP NonStop Open System Services (OSS) environment has reimplemented its
process checkpointing and caching features to improve fault-tolerance for OSS disk
files. New fileset configuration options enable separate control of checkpointing and
caching and are implemented according to whether the standard O_SYNC flag is used
for an OSS file open. (The nonstandard S_NONSTOP flag is now ignored.) The new
default configuration settings provide the recommended minimum level of fault
tolerance, but it is possible to configure a fileset for legacy fault-tolerant behavior.
The checkpointing and caching features are configured using OSS Monitor Subsystem
Control Facility (SCF) module command options, rather than the storage subsystem
SCF DISK command. (The new fault-tolerant behavior requires disk caching to remain
enabled by the storage subsystem.) For more information, see the Open System
Services Management and Operations Guide.
Migration
Applications that use S_NONSTOP should be recoded to use O_SYNC.
If a site considers legacy fault-tolerant behavior to be preferable to the defaults used by
the updated product modules, that behavior must be manually reconfigured after
installation.
Fallback
If you fall back, filesets that you configure to use the new options prior to fallback will
no longer use those options.